130 



LIFE IN THE SEA 



[CH. 



samples of water taken from the North Atlantic, 

 the equatorial seas, and the Antarctic Ocean. The 

 following figures apply to northern seas, and each is 

 an average based on from 15 to 30 samples made in 

 each month of each of the years mentioned. 



Inorganic nitrogen compounds present per litre of water 

 from the North Sea and Baltic in the years 1904-6. 

 The figures represent milligrams. The proportions are 

 therefore parts per million of sea-water. 



We may consider along with these results those 

 of the recent Antarctic voyage of the German ship 

 ' Gauss/ and also some observations made in tropical 

 seas. Combining the results and ' rounding off' the 

 numbers we find that : 



Water from the Antarctic contained about 0-5 part per million 

 ,, ,, Equatorial seas ,, 0*1 ,, ,, 



,, ,, North Atlantic ,, 0-15 ,, ,, 



of inorganic nitrogen compounds. 



All these results apply to water taken from the 



